The present invention relates to improvements in metal refining converter installations. Such installations, especially those incorporating open-topped vessels that are pivotable about a horizontal axis between positions of charging, refining, and pouring, require the vessel to be surrounded by a gas-containment enclosure in order to prevent the escape of high temperature effluent gases and other materials to the atmosphere. Such enclosures must be provided with access openings to enable the converter vessel to be charged with scrap metal and/or molten pig iron. In practice, these openings are covered by large movable panels or doors which, after a period of use, become deformed as a result of thermally induced warpage or as a result of physical damage thereby destroying the effectiveness of the seals and, thus, enabling effluent to leak to the atmosphere.
Gas enclosure structures of the type in question which include movable panels to cover access openings to the converter are as described in U.S. Pat. No. 4,076,223 to E. G. Schempp.
Ideally an effective gas seal could be obtained between the panels and the adjacent enclosure structure by tight metal-to-metal contact between the members; however, in practice this form of gas seal is totally impractical in the concerned environment due to the inability to keep the mating seal surfaces free from particulates and also due to the fact that after prolonged use the panels and adjacent enclosure wall structure become deformed due to thermally induced warpage and physical damage so as to destroy any effective seal that may originally have existed between the mating seal surfaces.
It has been contemplated to employ water or sand seals about the seams between the movable panels and adjacent enclosure structure but such seals are gravity dependent and, accordingly, are operative only along those seams that are horizontally disposed, such as adjacent the top or bottom edges of the movable panels. Their use to seal the vertically disposed seams as exist between the facing ends of the movable panels when they are closed and between the remote ends of the panel and the adjacent enclosure wall structure is technically unfeasible.
It has also been contemplated to seal openings in converter enclosure structures by means of what is commonly termed an "air curtain" as shown in U.S. Pat. No. 3,724,827 to A. T. Dortenzo, but the use of such seals is possible only in a region of the enclosure that is not subject to high intensity gas discharges. Their use in the region of the enclosure charging doors is impractical especially when the enclosed converter is of the "bottom-blown" type since this region of the enclosure is oftentimes subject to impingement by high velocity gas discharge, as for example, when the open top of the vessel is rotated into facing relation with the doors during metal sampling stages of the process. "Air curtain" seals are otherwise undesirable in converter enclosure applications due to the fact that the amount of air flow required to effectively seal the enclosure openings must be of such magnitude as to require the use of fans having extremely high capacity with a concomitantly high operating expense.
It is accordingly to the solution of the abovementioned problems that the present invention is directed.